• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.533-542
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• 2016

We investigate fluidization characteristics of the mixture of rice husk, silica sand and rice husk ash as a preliminary study for valuable utilization of rice husk ash obtained from gasification of rice husk in a fluidized bed reactor. As experiment valuables, the blending ratio of rice husk and sand (rice husk: sand) is selected as 5:95, 10:90, 20:80 and 30:70 on a volume base. Rice husk ash was added with 6 vol% of rice husk for each experiment and air velocity to the reactor was 0~0.63 m/s. In both rice husk/sand and rice husk/sand/ash mixture, the minimum fluidization velocity (Umf) is observed as 0.19~0.21 m/s at feeding of 0~10 vol.% of rice husk and 0.30 m/s at feeding of 20 vol.% of rice husk. With increasing the amount of rice husk up to 30 vol.%, $U_{mf}$ can not measure due to segregation behavior. The mixing index for each experiment is determined using mixing index equation proposed by Brereton and Grace. The mixing index of the mixture of rice husk/sand and rice husk/sand/ash was 0.8~1 and 0.88~1, respectively. The optimum fluidization condition was found for the good mixing and separation of rice husk ash.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.761-766
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• 2015

This study investigated the effect of protease on quality characteristics of sponge cake. Protease was used at levels of 0.0005 U (PC-1), 0.0010 U (PC-2), 0.0015 U (PC-3), and 0.0020 U (PC-4) for sponge cake preparation. Amylogram showed the setback was significantly decreased in comparison with the control (P<0.05). Height and baking loss rate of control sponge cake were $4.24{\pm}0.18cm$ and $12.01{\pm}0.29%$, respectively. PC-3 and PC-4 showed increased heights of $5.22{\pm}0.16$ and $5.24{\pm}0.11cm$ as well as slightly increased baking loss rates of $12.71{\pm}0.31%$ and $12.89{\pm}0.61%$, respectively. Specific volume and color difference measurements of control showed a specific volume of $3.53{\pm}0.06mL/g$, crust color difference of $53.05{\pm}0.28$, and crumb color difference of $29.84{\pm}0.52$. Measurements of specific volume, crust color, and crumb color of PC-3 and PC-4 were $4.18{\pm}0.02mL/g$, $56.19{\pm}0.84$, $29.05{\pm}0.43$, $4.21{\pm}0.02mL/g$, $56.85{\pm}0.43$, and $29.45{\pm}0.47$, respectively. Firmness measurements showed that the control had the highest firmness. PC-3 and PC-4 were effective at improving the shelf-life of sponge cake as indicated by reduced firmness. Sensory evaluation results demonstrated that all samples scored higher than the control. Throughout the results, the addition of protease increased volume and improved quality characteristics of sponge cake.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.614-619
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• 2005

The water-soluble defoamers were fabricated by the mixing polyol, modified silicon resin, silicon resin and surfactant. For the defoamers, the various properties such as phase-separation time, viscosity and defoamerability were examined. The phase-saparation time of PPG mixtures was found to be PPG 400>PPG 3,000>PPG 1000. When PPG 1000 was mixed, mixtures represented the excellent defoamerability. The phase-saparation time of silicon resin mixtures was TSF-451-350>TSF-451-200>TSF-451-50. As more of high molecular silicon resin was mixed, the resulting mixtues showed reduced defoamerability. When the TSF-451-50 was mixed, the mixture's volume was increased because of the reduction of solubility. The modified silicon resin was smoothly dispersed in water, but the compatibility with PPG was not good. The defoamerability of surfactant was SPAN 20>SPAN 60>SPAN 80. SPAN 80 showed good miscibility for the silicon resin, but not good for YAS 6406 or PPG 1000.

• Journal of the Korean Chemical Society
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• v.33 no.2
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• pp.164-167
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• 1989

The rate for the aquation of $trans-[Cr(tmd)_2FX]^+(X=F^-,\;Cl^-)$ ion in aqueous acidic solution has been measured by spectrophotometric method at various temperatures and pressures. The rate constants are increased with increasing temperatures and pressures. The values of activation entropy are 5.2 eu for $trans-[Cr(tmd)_2F_2]^+$ and -16.62 eu for $trans-[Cr(tmd)_2FCl]^+$ ions. Activation volumes have all negative values and lie in the limited range $-3∼-2\;cm^3mol^{-1}$ for $trans-[Cr(tmd)_2F_2]^+$ and $-8∼-7\;cm^3mol^{-1} for $trans-[Cr(tmd)_2FCl]^+$ ion. From the above results, we may deduce that the mechanism for the aquation of $trans-[Cr(tmd)_2F_2]^+$ and $trans-[Cr(tmd)_2FCl]^+$ ions is interchange-associative mechanism and dissociative mechanism respectively.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.254-261
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• 2009

The maxillary sinus bone graft procedure is one of the predictable and successful treatments for the rehabilitation of atrophic and pneumatized edentulous posterior maxilla. Materials used for maxillary sinus floor augmentation include autogenous bone, allogenic bone, xenogenic bone and alloplastic materials. Among them, autogenous bone grafts still represents 'gold standard'for bone augmentation procedures. We selected the mandibular ramus area as a donor site for the autogenous bone graft because of low donor site morbidity. We performed maxillary sinus bone graft procedures with implant placement using particulated ramal autobone and bovine bone mixture, and got good results. This is a preliminary report of the maxillary sinus bone graft using particulated ramal autobone and bovine bone, requires more long-term follow up and further studies.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.223-230
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• 1990

Gelatinization properties of heat-moisture treated Olchal(japonica) and Hankangchalbyeo(j x indica) waxy rice starches were compared. The blue value, light transmittance of starch suspension and viscosity in sodium hydroxide solution were similar between two starches. Olchal starch showed lower water binding capacity, swelling power md peak viscosity by amylograph than Hankangchalbyeo starch. Upon heat-moisture treatments all above parameters were decreased. The critical sodium hydroxide concentration for gelatinization was increased by treatments. The initial pasting temperature of Olchal starch was higher than that of Hankarlgchalbyeo. All amylograph reference points increased by the treatments, except the maximum viscosity or 2l% moisture-treated Olchal starch. Starches treated at 18% moisture level showd the highest value of consistency index. The activation energy of consistency index for gelatinized Olchal starch was lower than that for Hankangchalbyeo starch. The heat-moisture treatments had no effect on activation energy.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.377-388
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• 2005

Effects of silkworm powder addition on rheological properties of dough and quality characteristics of bread were investigated. Protein content of silkworm powder was 53,98%, much higher than 12.46% of wheat powder, Crude fiber, fat, and pretense contents of silkworm powder were higher than those of wheat flour, Acid analysis revealed glutamic acid content was highest 4,046.16 mg thus, significant depreciation of breadmaking was expected due to weakened gluten structure or dough. Addition of silkworm powder(optimum at 2%) with pretense inactivated by heat treatment resulted in significant improvement of volume and bread quality, with external and internal scores close to those of the control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1201-1205
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• 2004

The purpose of this study was to develop functional breads added with Ganoderma lucidum (GL) extract which was well known for preventing various adult diseases and cancer. It was observed that bitter taste was increased with up to 8％ GL extract while dough volume was increased at the first dough fermentation period and baking loss reduction was decreased. In terms of sensory evaluation, there were not so much significant differences with 2％ added GL extract. In 4, 6, 8％ added GL extract bread, it was found that 4％ was ordinary and 6％ and 8％ were bad compared to the control bread. The bread with 2％ added GL extract was excellent, 4％ was ordinary and 6, 8％ was badly evaluated in the internal texture. It's possible to make the functional breads baking with 2％ GL extract which is similar to the control breads based on the above results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1367-1372
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• 2004

The effects of barley bran substitution on the quality of sugar-snap cookie and muffin were investigated using physical tests and sensory evaluation. Barley bran contained 29.04% starch, 16.23% protein, and 8.57% lipid. They were formulated by substituting the flour with the barley bran of 0, 10, 20, and 30%. Increasing levels of barley bran substitution reduced cookie spread, lightness, top grain scores and other sensory qualities. Cookies with 10% barley bran substitution, however, were not significantly different from the control cookies in sensory characteristics, and cookies with 20% barley scored well above the minimum acceptance level of 5 on a 9-point scale. Although the barley bran decreased muffin volume and had a deleterious effect on crumb grain, muffins with 10% bran had acceptable sensory properties. The physical and sensory results indicated that barley bran could be added to cookie and muffin at replacement levels up to 20% without a large adverse effect on cookie and muffin quality.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.755-761
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• 2009

To a first approximation, phase behavior of a system becomes increasingly skew in proportion to the boiling point difference of system-forming constituents. Therefore, phase behavior data of a system of a large boiling point difference are to be experimentally measured for thorough understanding of the thermodynamic characteristics of such system. In this work, isobaric vapor-liquid equilibrium of a mixture consisting of toluene and cresol, which shows a large boiling point difference of nearly $100^{\circ}C$ and is consequently expected to be considerably nonideal, was measured by using a recirculating equilibrium cell at various subatmospheric pressures ranging from 10 kPa to 60 kPa. The measured VLE data were correlated with NRTL and UNIQUAC models in a satisfactory manner and the accompanying thermodynamic consistency test represented soundness of the measurements. In addition, the excess molar volume of the mixture was also measured with a vibrating densitometer and correlated with a Redlich-Kister polynomial. A negative excess volume prevailed over the whole concentration range, which indicates a favorable attraction between toluene and cresol isomers and results in an extensive miscibility.